A formal decision on a new launch date for the shuttle Discovery was in limbo Wednesday pending final resolution of a persistent fuel leak and a decision on what to do about two sluggish valves, but engineers hope to announce a late September target by the end of the week.

Discovery skipper Frederick Hauck said in an interview Tuesday it would be prudent to resolve the leak issue by proving the problem will not get worse during blastoff before proceeding with the announcement of a launch date."I would think that would be a little premature, but then both of (the problems) may be resolved in the next day or two," he said. "I know that folks would like very much to get a date out in the next day or two."

Agency planners indicated Monday that a recommendation on a launch date, ranging from Sept. 25 to Sept. 29, would be discussed Tuesday for a possible announcement as early as Wednesday.

NASA managers decided Tuesday that more time was needed to nail down a target date, but most engineers said a launch in the last week of September remained the space agency's goal.

The hydrogen leak was detected aboard Discovery during two recent fuel loading exercises and it was traced to a 4-inch "quick-disconnect" fitting in the shuttle's belly. While the leak is small, it increased sharply when Discovery's engines were test fired Aug. 10.

Don Puddy, director of flight crew operations at the Johnson Space Center, said in an interview that managers should have a better idea about their options by the end of the week.

"I think by the end of the week we'll certainly have picked a posture where we're either going to feel we have enough data, that everybody feels comfortable to press on as is, or that we need some additional testing before we're going to feel comfortable," he said. "Or we're going to need to make a systems change."